A rock bolt may be used to stabilise a rock mass formation by the steps of drilling a drill hole in the rock mass, inserting the rock bolt into the drill hole and then securing the rock bolt in place with a cement grout or a resin. It is known to use a self-drilling rock bolt such that the second step is avoided.
An apparatus for connecting supply pipes to the inner channel of a rock bolt is described in Applicant's prior application DE 10 2005 050 929.0-24 A1. The apparatus disclosed in this document delivers plastics components separately to the inner channel of the rock bolt which has a static mixer to mix the components. This document discloses selecting the plastics components so that their cure time is substantially the same as the time for filling the inner channel and the drill hole surrounding the anchor rod. Thus the plastic components harden in such a way that the anchor rod does not longer fall out of the drill hole and no plastics material seep out of the drill hole. This method enables anchor rods to be set in place quickly as it is not necessary to wait for hardening or to seal the drill hole.